Aplastic Anemia

Dr.CSBR.Prasad, M.D.,

Definition

• Aplastic anemia refers to a syndrome of chronic primary hematopoietic failure and attendant pancytopenia

– Anemia

– Neutropenia, and

– Thrombocytopenia

Mechanisms

Stem cell defect:

• Autoimmune (Most common)

• Inherited or

• Acquired

Major Causes of Aplastic Anemia

Aplastic Anemias

Fanconi anemia

• AR disorder

• Defect in DNA repair

• Marrow hypoplasia

• Hypoplasia of kidney, spleen

• Hypoplastic anomalies of bone – Thumb, Radius

Fanconi anemia

Aplastic Anemias - Pathogenesis

Environmental factors trigger the production of genetically altered stem cells

1. Immunologically mediated suppression of stem cells

By cytokines released by T cells

2. Intrinsic abnormality of stem cells

↓ proliferation & differentiating capacity

Pathophysiology of aplastic anemia

Aplastic Anemias - Morphology

• BM Aspiration – Dry tap

• BM biopsy – Diagnostic

• BM – markedly hypocellular

• Empty marrow spaces - fat, fibrous tissue, lymphocytes, plasma cells

Aplastic anemia

Morphology

Aplastic Anemias

PBS

• NCNC, slight macrocytosis

• Reticulocytosis is absent

• Leukopenia

• Thrombocytopenia

Clinical Features

• Can occur at any age

• Onset is usually insidious

• Initial manifestations vary depending on the affected cell line

• Splenomegaly is absent

• Reticulocytopenia is the rule

If it is present, the diagnosis of aplastic anemia should be

seriously questioned

Aplastic Anemia

• DD

– MDS

– Aleukemic leukemia

Treatment

• Allogenic BMT

• Antithymocyte globulin along with cyclosporine

Mary Curie

Pure Red Cell Aplasia

• It’s a primary marrow disorder in which only erythroid progenitors are suppressed

• Causes:

– Thymoma

– Large granular lymphocytic leukemia

– Drug exposures

– Autoimmune disorders

– Parvovirus infection B19

Myelophthisic anemia

Myelophthisic anemia

SOL destroys BM architecture & depresses its productive capacity

Causes

1. Metastatic cancer – lung, breast, prostate, thyroid

2. Multiple myeloma, leukemia, lymphoma

3. Myelofibrosis

PBS - Leukoerythroblastosis

Polycythemia

Polycythemia

• Myeloproliferative disorder

– Unregulated proliferation of erythroid elements in BM

– ↑ Erythrocyte concentration in peripheral blood

• Also ↑ other blood cells

• Synonyms: Polycythemia rubra vera, primary polycythemia, erythemia

Polycythemia

• Polycythemia Vera – primary

• Secondary Polycythemia – Appropriate to erythropoietin production

• High altitude

• COPD

• Obesity

– Inappropriate to erythropoietin production • Tumors – RCC, HCC, uterine leiomyoma

• Renal ischemia

– Familial Polycythemia

• Relative Polycythemia – Gaisbock’s syndrome

– Dehydration

Polycythemia Vera

• Unknown cause

• Possible mechanisms

– Erythropoietin independent proliferation of neoplastic stem cells

– Hypersensitivity of erythroid stem cells to erythropoietin

– Hypersensitivity of erythroid stem cells to insulin growth factors

– Abnormal GF that act on normal stem cells

Polycythemia Vera – C/F

• 40- 60 years

• M > F

• Gradual in onset

• Headache, weakness, pruritis, weight loss, fatigue

• GIT bleeding, menorrhagia, hemoptysis

• MI, Renal vein thrombosis, cerebral ischemia

Plethora of polycythemia

Polycythemia Vera – C/F

• Splenomegaly – 75%

• Hepatomegaly – 50%

• Hypertension – 50%

• Long standing cases – myelofibrosis – 30%

• 10% cases develop into acute leukemia

Polycythemia Vera – Lab findings

• Absolute Erythrocytosis: > 6-10millions/cumm

• Hemoglobin: > 18 gm%

• PCV > 48% in F, > 52% in M

• ESR – 2-3mm/ hour

• Reticulocyte count – normal / mildly increased

• Leukocytosis: > 12,000/mm3

• Platelet count - ↑

• PBS – NNBP, MCHC

Polycythemia Vera – Lab findings

• BM –

– hypercellular

– 95% cases - ↑ megakaryocytes

– ↑ reticulin

• Treatment

– Phlebotomy

– Myelosuppresive therapy

E N D

Dr.CSBR.Prasad, M.D.,

Associate Professor of Pathology,

Sri Devaraj Urs Medical College,

Kolar-563101,

Karnataka,

INDIA.

csbrprasad@reiffmail.com